get original pdf page size

get-page-size.js

/** @typedef {import("pdfjs-dist/lib/display/api.js").PDFDocumentProxy} PDFDocumentProxy */
/**
 * @param {String} pdfUrl
 * @param {PDFDocumentProxy} documentProxy - pdf.js document proxy object
 */
const handleGetPageSize = async ({ pdfUrl, documentProxy }) => {
  const documentKey = archives.value.find((archive) => archive.documentPdfUrl === pdfUrl).key;

  const pageBaseList = Array.from({ length: documentProxy.numPages });
  const pageOriginalSizePromise = pageBaseList.map(async (_item, index) => {
    const page = await documentProxy.getPage(index + 1);
    const [, , width, height] = page.view;

    return { [documentKey]: { [index + 1]: [width, height] } };
  });

  const pageOriginalSize = await Promise.all(pageOriginalSizePromise);

  const mergedKeys = merge(...pageOriginalSize);

  originalPageSizes.value = { ...originalPageSizes.value, ...mergedKeys };
};